Blinks of the mind: memory effects of attentional processes

If 2 words are presented successively within 500 ms, subjects often miss the 2nd word. This attentional blink reflects a limited capacity to attend to incoming information. Memory effects were studied for words that fell within an attentional blink. Unrelated words were presented in a modified rapid serial visual presentation task at varying stimulus-onset asynchronies, and attention was systematically manipulated. Subsequently, recognition, repetition priming, and semantic priming were measured separately in 3 experiments. Unidentified words showed no recognition and no repetition priming. However, blinked (i.e., unidentified) words did produce semantic priming in related words. When, for instance, ring was blinked, it was easier to subsequently identify wedding than apple. In contrast, when the blinked word itself was presented again, it was not easier to identify than an unrelated word. Possible interpretations of this paradoxical finding are discussed.     

Effects of hand orientation and delay on the verbal judgment of haptically perceived orientation

We examined the haptic perception of orientations of a single bar throughout the horizontal plane using a verbal response: participants were to assign a number of minutes to the orientation of a bar defined with respect to the stimulus table. Performance was found to be systematically biased. Deviations were consistent with, yet much smaller than, those resulting from haptic motor matching tasks. The size and direction of the deviations were found to correlate with hand orientation, and not to depend on spatial location per se, suggesting a role for hand-centred reference frames in biasing performance. Delaying the response by 10 s led to a small improvement only of right-hand perceptions, indicating different hemispheric involvement in processes involved in retaining and/or recoding of haptic orientation information. Also the haptic oblique effect was found with the current verbal response. Importantly, it was affected neither by hand orientation nor by delay, suggesting that the oblique effect is independent of the aforementioned deviations in orientation perception.     

The role of the locus coeruleus in mediating the attentional blink: a neurocomputational theory

The attentional blink refers to the transient impairment in perceiving the 2nd of 2 targets presented in close temporal proximity. In this article, the authors propose a neurobiological mechanism for this effect. The authors extend a recently developed computational model of the potentiating influence of the locus coeruleus-norepinephrine system on information processing and hypothesize that a refractoriness in the function of this system may account for the attentional blink. The model accurately simulates the time course of the attentional blink, including Lag 1 sparing. The theory also offers an account of the close relationship of the attentional blink to the electrophysiological P3 component. The authors report results from two behavioral experiments that support a critical prediction of their theory regarding the time course of Lag 1 sparing. Finally, the relationship between the authors' neurocomputational theory and existing cognitive theories of the attentional blink is discussed.     

The effects of progressive sleep loss on a lexical decision task: Response lapses and response accuracy

A lexical decision task was used in a paradigm testing the effects of sleep loss and fatigue on performance during a 72-h period of sleep deprivation. The data were partitioned into categories of response lapses, response accuracy, and the signal detection measures of discriminability (d’) and bias (β). Response lapses increased as a function of sleep loss and were fitted best by a composite equation with a major linear component and a minor rhythmic component. Response accuracy decreased as a function of sleep loss, with the rate of decrease being greater for nonwords than for words. Although d’ was higher for right visual field (RVF), it decreased for both fields almost linearly as a function of sleep deprivation. The rate of decrease for RVF stimulation was greater than for left visual field (LVF) stimulation, β did not change monotonically as a function of sleep loss, but showed strong circadian rhythmicity, indicating that it was not differentially affected by sleep loss per se.     

Procedural differences in processing intact and degraded stimuli

In three experiments, the extent to which the processing of a visual stimulus profits from equal processing demands of a preceding stimulus was examined. Subjects identified two subsequently presented digits (S1 and S2) that were either intact or degraded by noise, yielding four combinations of stimulus quality, In Experiments 1 and 2, S1 and S2 differed with respect to the values of the digits, so that stimulus quality was the only dimension of possible agreement. The results revealed a faster response to S2 when the stimulus pairs were homogeneous (both intact or both degraded stimuli) than when they were not homogeneous (degraded-intact pairs and intactdegraded pairs, respectively), The occurrence of equal values of S1 and S2 (Experiment 3) tended to magnify thishomogeneous-stimulus effect, but was not a prerequisite for its occurrence, Relative to conditions considered to be neutral, the homogeneous-stimulus effect proved to be due to deviant behavior following the processing of a degraded S1. The suggestion that this reflects the involvement of controlled processing is discussed.     

USING HIGH-PROBABILITY INSTRUCTION SEQUENCES WITH FADING TO INCREASE STUDENT COMPLIANCE DURING TRANSITIONS

Making efficient transitions from one instructional activity to another has been shown to increase academic learning time and therefore student achievement. Because compliance with teacher instructions is a prerequisite for efficient transitions, we sought to determine if high-probability (high-p) instruction sequences issued by a classroom teacher would increase student compliance and decrease latency to comply during transitions. Three children in a regular second-grade classroom participated. Each day at the beginning of morning calendar time, the teacher issued five instructions to the class as a group while compliance data were recorded for the 3 target students. Following baseline, a multielement design was used to examine the effects of the high-p instruction sequence. We then systematically faded the number of instructions included in the high-p sequence as a means of transferring stimulus control to low-probability instructions. The procedure was effective for 2 of the 3 participants, and the results were maintained at 2-and 3-week follow-up. The implications of these findings for group applications of the high-p instruction sequence in regular education classrooms are discussed.     

Anxiety and motor behavior: a review

Anxiety and related terms were defined by conceptually distinguishing between "state" and "trait" anxiety and between anxiety, stress and fear. The literature concerned with the anxiety-motor behavior relationship was reviewed using the state-trait anxiety distinction. After outlining the general notions of drive theory as related between the Taylor Manifest Anxiety Scale (MAS) and motor behavior in the absence or in the presence of a stressor, and on those studies using anxiety scales other than MAS. The accumulated evidence failed to reveal any consistent trends in these three areas. The use of drive theory and the MAS to predict motor behavior ws shown not to be a viable approach. Two alternative approaches were briefly outlined.     

THE EFFECTS OF INSTRUCTIONAL MATCH AND CONTENT OVERLAP ON GENERALIZED READING PERFORMANCE

This study examined the effects of instructional match and content overlap on students' ability to generalize from passage reading instruction. Four students with mild disabilities served as participants. Using a multielement design, students were instructed with passages at two levels of text difficulty (instructionally matched vs. instructionally mismatched), and generalization was assessed with passages at two levels of similarity to those instructed (low vs. high content overlap). Results indicated that students' oral reading accuracy and fluency showed the greatest degree of generalization when instructional materials were matched to the students' skill level and assessment materials were similar to those used during instruction. Moreover, these results were maintained at 1-month follow-up. The implications of these findings for classroom reading instruction and the assessment of students' reading skills are discussed.